Simultaneous Multiwavelength Observations of the Blazar 1ES 1959+650 at a Low TeV Flux

Journal Article · Sun Jun 01 04:00:00 EDT 2008 · Astrophysical Journal

DOI:https://doi.org/10.1086/586731; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21255757

Tagliaferri, G; Ghisellini, G ^[1]; Foschini, L ^[2]; Maraschi, L ^[3]; Tosti, G ^[4]; Albert, J; Berger, K ^[5]; Aliu, E ^[6]; Anderhub, H; Biland, A ^[7]; Antoranz, P; Barrio, J A ^[8]; Baixeras, C ^[9]; Bartko, H; Bock, R K ^[10]; Bastieri, D; Bigongiari, C ^[11]; Becker, J K ^[12]; Bednarek, W ^[13]; Bedyugin, A ^[14]

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1. INAF/Osservatorio Astronomico di Brera, via Bianchi 46, 23807 Merate (Saint Lucia) (Italy)
2. INAF/IASF-Bologna, Via Gobetti 101, 40129 Bologna (Italy)
3. INAF/Osservatorio Astronomico di Brera, via Brera 28, 20121 Milano (Italy)
4. Osservatorio Astronomico, Universita di Perugia, Via B. Bonfigli, 06126 Perugia (Italy)
5. Universitaet Wuerzburg, D-97074 Wuerzburg (Germany)
6. IFAE, Edifici C, E-08193 Bellaterra (Barcelona) (Spain)
7. ETH Zurich, CH-8093 Switzerland (Switzerland)
8. Universidad Complutense, E-28040 Madrid (Spain)
9. Universitat Autonoma de Barcelona, E-08193 Bellaterra (Spain)
10. Max-Planck-Institut fuer Physik, D-80805 Muenchen (Germany)
11. Universita di Padova and INFN, I-35131 Padova (Italy)
12. Universitaet Dortmund, D-44227 Dortmund (Germany)
13. University of Lodz, PL-90236 Lodz (Poland)
14. Tuorla Observatory, Turku University, FI-21500 Piikkioe (Finland)

We present the results from a multiwavelength campaign on the TeV blazar 1ES 1959+650, performed in 2006 May. Data from the optical, UV, soft- and hard-X-ray, and very high energy (VHE) gamma-ray (E > 100 GeV) bands were obtained with the Suzaku and Swift satellites, the MAGIC telescope, and other ground-based facilities. The source spectral energy distribution (SED), derived from Suzaku and MAGIC observations at the end of 2006 May, shows the usual double hump shape, with the synchrotron peak at a higher flux level than the Compton peak. With respect to historical values, during our campaign the source exhibited a relatively high state in X-rays and optical, while in the VHE band it was at one of the lowest level so far recorded. We also monitored the source for flux spectral variability on a time window of 10 days in the optical-UV and X-ray bands and 7 days in the VHE band. The source varies more in the X-ray than in the optical band, with the 2-10 keV X-ray flux varying by a factor of {approx}2. The synchrotron peak is located in the X-ray band and moves to higher energies as the source gets brighter, with the X-ray fluxes above it varying more rapidly than the X-ray fluxes at lower energies. The variability behavior observed in the X-ray band cannot be produced by emitting regions varying independently and suggests instead some sort of 'standing shock' scenario. The overall SED is well represented by a homogeneous one-zone synchrotron inverse Compton emission model, from which we derive physical parameters that are typical of high-energy peaked blazars.

• OSTI ID: 21255757
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 679; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
99 GENERAL AND MISCELLANEOUS
BL LACERTAE OBJECTS
ENERGY SPECTRA
GAMMA RADIATION
HARD X RADIATION
SATELLITES
TELESCOPES
TEV RANGE
X-RAY GALAXIES